Oral appliance



FIG. 1 is a front perspective view of an oral appliance according to a first embodiment of my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a left side elevation view thereof, the right side elevation view being a mirror image thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The features shown in broken lines are environmental only and form no part of the claimed design. The dash-dot lines represent boundary lines that form no part of the claimed design. 

CLAIM The ornamental design for an oral appliance, as shown and described. 